This was told to me by Poet_with_a_Gun over on the Hoodlums forum and I thought I should share as Scrimshaw is an easy and beautiful artform
A medium (like ivory, bone, plastic, horn, antler)
A scratch tool (Like an awl, or a needle)
And ink (I used an old bottle of higgins I had laying around)
You take what you want to work one, if it's bone or something that's not smooth, you polish it up with fine sand paper and steel wool.
You can rub some beeswax onto the surface, and then you scratch out your image or pattern.
You then rub it over with ink, an then use our fine fine steel wool to polish the ink off. What stays is the stuff in the grooves of your art work. (Which is why you polish and smooth and wax it first, so you don't have ink in pores and grooves you didn't make).
This website has some EXCELLENT info on scrimshaw.http://findermaker.blogspot.com/2009/10/scrimshaw-made-simple.html